EurekAlert! -- A new research study suggests that asthma may be over-diagnosed by up to 30 per cent in Canadian adults. The study, led by Ottawa researcher Dr. Shawn Aaron, examined 496 people from eight Canadian cities who reported receiving a diagnosis of asthma from a physician. When the individuals were retested for asthma using the accepted clinical guidelines, it was found that 30 per cent had no evidence of asthma. Two thirds of these individuals were able to safely stop taking asthma medications. The results are published in the November 18, 2008 edition of the Canadian Medical Association Journal.